Handle null HostID on calendar webhook endpoint

changes/10744-calendar-webhook-deleted-hosts

@@ -0,0 +1 @@
+* Fixed bug with calendar/webhook endpoint that caused an error if the calendar event relates to a deleted host.

ee/server/service/calendar.go

@@ -75,6 +75,14 @@ func (svc *Service) CalendarWebhook(ctx context.Context, eventUUID string, chann
 		}
 		return err
 	}
+
+	// Check if the event belongs to a deleted host ... in which case we do a noop (the event will eventually be
+	// removed by the cleanup CRON job)
+	if eventDetails.HostID == nil {
+		svc.authz.SkipAuthorization(ctx)
+		return nil
+	}
+
 	if eventDetails.TeamID == nil {
 		// Should not happen
 		return fmt.Errorf("calendar event %s has no team ID", eventUUID)
@@ -196,8 +204,13 @@ func (svc *Service) processCalendarEvent(ctx context.Context, eventDetails *flee
 		}
 
 		var hosts []fleet.HostPolicyMembershipData
-		hosts, err = svc.ds.GetTeamHostsPolicyMemberships(ctx, googleCalendarIntegrationConfig.Domain, team.ID, policyIDs,
-			&eventDetails.HostID)
+		hosts, err = svc.ds.GetTeamHostsPolicyMemberships(
+			ctx,
+			googleCalendarIntegrationConfig.Domain,
+			team.ID,
+			policyIDs,
+			eventDetails.HostID,
+		)
 		if err != nil {
 			return "", false, err
 		}
@@ -242,7 +255,7 @@ func (svc *Service) processCalendarEvent(ctx context.Context, eventDetails *flee
 			return ctxerr.Wrap(ctx, err, "save calendar event body tag")
 		}
 		_, err = svc.ds.CreateOrUpdateCalendarEvent(ctx, event.UUID, event.Email, event.StartTime, event.EndTime, event.Data,
-			event.TimeZone, eventDetails.HostID, fleet.CalendarWebhookStatusNone)
+			event.TimeZone, *eventDetails.HostID, fleet.CalendarWebhookStatusNone)
 		if err != nil {
 			return ctxerr.Wrap(ctx, err, "create or update calendar event")
 		}

server/datastore/mysql/calendar_events_test.go

@@ -83,7 +83,7 @@ func testUpdateCalendarEvent(t *testing.T, ds *Datastore) {
 	require.NoError(t, err)
 	assert.Equal(t, strings.ToUpper(eventUUIDNew), eventDetails.UUID)
 	assert.Equal(t, *calendarEvent, eventDetails.CalendarEvent)
-	assert.Equal(t, host.ID, eventDetails.HostID)
+	assert.Equal(t, host.ID, *eventDetails.HostID)
 	assert.Nil(t, eventDetails.TeamID)
 
 	// TODO(lucas): Add more tests here.

server/fleet/calendar_events.go

@@ -60,7 +60,7 @@ func (ce *CalendarEvent) SaveDataItems(keysAndValues ...string) error {
 type CalendarEventDetails struct {
 	CalendarEvent
 	TeamID *uint `db:"team_id"` // Should not be nil, but is nullable in the database
-	HostID uint  `db:"host_id"`
+	HostID *uint `db:"host_id"`
 }
 
 type CalendarWebhookStatus int

server/service/integration_enterprise_test.go

@@ -14399,6 +14399,14 @@ func (s *integrationEnterpriseTestSuite) TestCalendarCallback() {
 	require.Len(t, team1CalendarEvents, 1)
 	assert.Equal(t, previousEvent, team1CalendarEvents[0])
 
+	err = s.ds.DeleteHost(ctx, host1Team1.ID)
+	require.NoError(t, err)
+	_ = s.DoRawWithHeaders("POST", "/api/v1/fleet/calendar/webhook/"+eventRecreated.UUID, []byte(""), http.StatusOK,
+		map[string]string{
+			"X-Goog-Channel-Id":     details.ChannelID,
+			"X-Goog-Resource-State": "exists",
+		})
+
 	// Trigger calendar should cleanup the events
 	triggerAndWait(ctx, t, s.ds, s.calendarSchedule, 5*time.Second)
 	assert.Equal(t, 0, calendar.MockChannelsCount())